


Oliver Queen and the Vengeance of Merlin

by thallata



Category: Arrow (TV 2012), Harry Potter - J. K. Rowling, The Flash (TV 2014)
Genre: Alternate Universe - Hogwarts, Gen
Language: English
Status: In-Progress
Published: 2015-06-26
Updated: 2015-06-26
Packaged: 2018-04-06 06:04:10
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,127
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4210815
Author URL: https://archiveofourown.org/users/thallata/pseuds/thallata
Summary: <blockquote class="userstuff">
              <p>Five years ago Oliver Queen went missing in the summer before his second year at Hogwarts. Now he's back in the Wizarding World and determined to make up for his father's mistakes. All he has to go on is a list of names and rumors of a great Undertaking. To help him he has the combat skills he was forced to hone, and an array of Dark Arts spells he can't let anyone know about. He'll also need the help of the smartest witch of her generation and the loyalty of a war wizard to overcome the forces arrayed against him. Will Oliver be able to outmaneuver those who seem set on plunging the Wizard and Muggle world alike into chaos?</p>
            </blockquote>





	1. A Return to School

Oliver Queen kept staring up at the castle as the carriages drew closer. The desire to not be here was clear in his posture, but his face was carefully blank. He hadn’t batted an eye at the thestrals pulling him, Tommy, Thea, and Laurel towards Hogwarts; the Island and everything after had exposed him to a lot of things he wasn’t going to be sharing. He forced a smile onto his face when Tommy made a joke, and tried to see this as an opportunity rather than an obstacle to working on the List.

“Come on Ollie, it’ll be great! The Gryffindor common room wasn’t the same without you. All those underclassmen were walking around like they owned the place,” Tommy lamented. Tommy had carried on like this for most of the time he visited Queen Manor over the summer. Oliver tried not to begrudge Tommy Merlyn the Head Boy badge; it was harder than he expected to not hate his friends for being the same people he had left, while he was twisted all out of shape.

“I’m sure it couldn’t have been that bad Meryln,” Laurel corrected, straightening her Ravenclaw Head Girl’s badge, “If anything, Gryffindor lost hundreds fewer points since you left Ollie.”

Oliver grimaced at the rebuke clear in her tone. Over the summer, she had begun to forgive him for her sister’s loss, but things were still a long way from good between them. She kept alternating between trying to draw him into reminiscing about Sara and yelling at him for her death. He couldn’t blame her; it was his fault after all.

“Well, it’s ok, Oliver always earned them back in Quidditch. And with you on the team again, Slytherin is never going to have a chance!” Tommy crowed, “It’ll be snitches all the way, just like old time.”

Oliver forced himself to smile at Tommy; he had no intention of playing Quidditch. If he had any hope of working on the List he couldn’t afford to have his spare time taken up with the pointless sport. 

“I wouldn’t want to compete with Speedy here for the honor,” he joked, slinging an arm over his sister. Among the many things he regretted was missing her sorting; he couldn’t be prouder that she was sorted into Gryffindor with him, rather than Slytherin like their parents had been.

“I told you not to call me that!” Thea yelled, though she didn’t fight her way out of the partial embrace like she would have before the Island. Thea kept alternating between sticking to his side to ensure that Oliver didn’t disappear again and asserting her independence by running off with the other 4th years. 

Oliver and Thea bickered good-naturedly for the rest of the trip to the castle. Oliver was starting to be almost glad that his mother had insisted that he finish his last year of school. She and Steele had strong-armed the board of directors into accepting him back for his N.E.W.T.s year. No one expected him to pass them of course, but they felt that a full Hogwarts’ education would help him guide the Queen legacy. And no one denied Moira Queen, so here he was in a carriage on his way to a school he had outgrown in the last 5 years. 

As the group exited the carriage, Thea dashed off to find the other Gryffindor 4th years. Other students were glancing curiously over at Oliver, but no one approached. He wasn’t surprised; they hadn’t really been his friends, just hangers-on really.

“So, I’m thinking this weekend we’ll through the biggest party this place as seen since the fall of the Dark Lord,” Tommy said as they walked into the castle proper.

“Don’t call him that,” Laurel snapped for the millionth time. There had been some conflict growing up, as one might expect. Tommy and Oliver came from some of the best-known Slytherin families after the Malfoys while Laurel’s father was of one of the best Aurors to make it through the last war. 

“Fine, fine,” Tommy waved it off like he always did, “Voldemort. Whatever. The point is: enormous party. This weekend. Time to get back in the game, man!”

“Sure, party,” Oliver responded, forcing himself to sound positive. A huge party was the last thing he wanted, but it could help him provide cover for the first name on the List, who was conveniently located in Hogsmeade.

They waved goodbye as they entered the Great Hall and split up for their separate house tables. Oliver glanced over at the sea of faces settling in, recognizing only a few people at each table. Besides Tommy and Thea, there was almost no one at the Gryffindor table he recognized. There was the Patil girl of course, and the Muggleborns Smith and Cooper, and Burke the Irish wizard, who shared the tower room with Oliver and Tommy. He nodded at the people he knew and settled in to wait for the sorting to start. Even when he had been a first year, the grandeur of Hogwarts failed to amaze him. Now he found the floating candles and ever-changing ceiling distracting. 

“I’m thinkin’ it’s going to be a good year for Gryffindor this year buddy,” Tommy quipped as the first student (Albert Abbott) was called up after the sorting hat had finished it’s song. 

After a short pause, followed by a hearty shout of “Hufflepuff!” Tommy grimaced in mock-pain. The first student was followed by a several more Hufflepuffs, two Ravenclaws and a Slytherin before the first student was sorted into Gryffindor. 

“You sure about that Tommy?” he asked, scanning the other tables while applauding for their new first year (Mike Grell). Oliver continued to carefully avoid looking at the Head Table, where Professor Lance had been glaring daggers at him the whole time. 

“Well, you’d think that people would prefer Professor Longbottom to Laurel’s dad,” Merlyn replied sulkily.

They waited politely, welcoming 12 new students into Gryffindor. Hufflepuff had gotten 19, Ravenclaw 12 and Slytherin 10. The students had turned hopefully towards the Headmistress, hoping she would quickly get the speech out of the way so they could eat. Oliver looked at her, ignoring Professor Lance’s heated look through sheer force of will. 

“Welcome students,” Headmistress McGonagall began in her rich Scottish brogue, “I know you’re hungry so I will keep this short.” 

After pausing for a laugh the Headmistress continued the yearly speech. Oliver tuned it out, impatient to get out of the Great Hall and get to work. He smiled slightly when he realized that was probably the only time he’d thought that in all his years here. His attention was drawn back to the headmistress when he caught his name.

“Please also welcome back Mr. Oliver Queen, year 7 of Griffindor. Finally, a few reminders: Hogsmeades weekend attendance requires permission of a guardian, the Forbidden Forest remains forbidden, and lastly, please remember that Hogwarts is a school so do try and learn something this year. And without further wait, dinner is served!”

 

 

 

As students of all years and houses rushed out of the Great Hall, Oliver was pulled aside by his Head of House.

“You’re sure you’re doing alright?” Neville Longbottom asked gently. He put a hand on Oliver’s shoulder but withdrew it when he tensed up.

“I’m fine,” and after a pause Oliver added, “sir.”

“Well, I might believe that if you had ever called me, or any Professor, sir before,” Longbottom said with a smile.

“Sorry Professor,” Oliver forced his face to smile, “I’m just getting used to everything again. I bet by the end of the week you’ll be giving me detentions just like before.”

“While I would be glad to have you back to your old self Mr. Queen, I would be even gladder to see you apply your mind to more than finding ways to smuggle alcohol into the common room.”

“I’m sure I can come up with something to keep myself occupied,” Oliver quipped as he sauntered backwards. Professor Longbottom rolled his eyes, but waved him off. Once the he was out of sight, Oliver dropped the smile and ducked into a secret passage that came out near Gryffindor tower. 

He gave the portrait the password ‘Merlin’s Beard’ (he was sure Tommy had picked that one), and hurried through the common room up to the 7th year boy’s room. He was the first one there; so he had time to take out the bundle he had brought from the Island, pull out his wand and Disillision the bag before cramming it under the bed. 

His mother had taken him to get a new wand as soon as they had left St. Mungo’s. His first wand had been willow with unicorn hair; it was not a wand meant for heavy spell slinging. His new wand was oak and dragon’s heartstring, and his mother had been taken aback when it had chosen him. This was a wand meant for curses and battle, and it felt so right in his hand. He had joked that maybe some of the Dark magic of the Island had stuck with him to explain the choice. It was almost disappointing how fast the vendor and his mother had jumped to agree that must be the case.

He was changing for bed when Tommy arrived and exclaimed, “Damn dude, what in Tartarus happened to you Ollie?”

Oliver grimaced and looked down, thankful that Merlyn could only see his back. The scars, tattoos and Mark on the front were even worse than the burns and tattoo on the back.

“The Island… there was a lot of Dark magic there,” Oliver lied while technically telling the truth. 

“No, not that, I head about… you know, 20% scars and all. I mean the muscles… You have a lot of muscles.”

“Well, you’d be surprised how much exercise you get when there aren’t any House Elves around, Tommy.”

“Heh, right Ollie,” he paused and then punched his friend in the shoulder and said, “We are gonna win so many Quidditch games!”

Oliver just smiled at Tommy and continued getting ready for bed; it was going to be an eventful week.


	2. An Exciting End to the First Week

**Summary for the Chapter:**

> Oliver's first week ends with an adventure he wasn't expecting.

The first week of term was as stressful as he had thought it would be; it was hard trying to go back to being just Oliver Queen, goof-off and oblivious pureblood, and pretending he was the same shallow jerk who had left 5 years ago was wearing on him. Thankfully, with the exception of Tommy and Thea, all the other Gryffindors were giving him plenty of space, and no one from the other houses other than Laurel had anything but superficial pleasantries to share.

Although he technically hadn’t taken any O.W.L.s, he had managed to do well enough on placement tests to be taking N.E.W.T.-level Defense Against Dark Arts, Herbology, Charms and Transfiguration. He was just as happy to be left out of Professor Snow’s Potions class, and he had purposefully thrown the exam for the waste of time that was History of Magic.

Going back to class again after so long away was strange to say the least. The strangest part was that he wasn’t taking all his classes with Tommy anymore; Tommy had selected the easiest possible schedule so he would be taking History of Magic, Herbology, Defense Against Dark Arts and Muggle Studies of all things. Laurel had of course taken the full load required for Auror training.

The Professors for his classes had all reacted differently to having the infamous Oliver Queen back in their classes again.

Professor Longbottom was almost dotting on him in Herbology; he kept checking on how Oliver was doing and let him know he could come by to talk if he needed anything. He kept pairing Tommy and Oliver together in a misguided hope that they would get up to the same pranks they had 5 years ago. Instead Neville Longbottom watched almost sadly as Oliver and Tommy quietly worked on transplanting the Triffid spores and repotting the Gingold.

Professor Flitwick seemed vaguely pleased to see improvements in Oliver’s charm techniques, but otherwise seemed to have forgotten he was ever gone. Oliver had been forced to do a lot of charms work during the time he had been gone, so he was for once well prepared for a class. He had even managed to earn house points for performing a charm, a first for him. 

The Transfiguration Professor Rex Mason was new to Oliver. He was such a skilled Transfigurationist that he kept one arm transfigured into a different material every day. Mason was apparently popular with the rest of the class, and seemed to really care about his subject, though he was also as strict as McGonagall was rumored to have been. Oliver still struggled with this subject, and Tommy wasn’t in the class to cover for him, so he had to work twice as hard as on all his other classes combined. Still, he managed to make it through the week without any major incidents.

His first class back in Defense Against the Dark Arts started poorly, and quickly and inevitably went downhill. Professor Lance stalked into class and demanded Oliver describe the classes of shield charms. When he successfully did so, Lance took points for “sass”, and taunted that Oliver could at least learn even if he couldn't perform. Tommy then unhelpfully volunteered Oliver to cast Protego. Once he had done that, rather than earning house points he actually ended up in a pseudo-duel with Professor Lance. If Oliver hadn’t seen where things were going and thrown himself into a Jelly-Legs hex, he was pretty sure they would have ended up in the hospital wing. Or worse. Oliver then received detention for failing to avoid such a simple hex. 

That had just been class on Monday. 

All told, Oliver had lost 30 points in D.A.D.A., gained 5 in Charms, and another 15 in Herbology as Professor Longbottom tried to keep Gryffindor from plummeting to the bottom of the ranking. Additionally he had detention on Friday night where he had spent hours assembling ‘So you’ve caught Lycanthropy’ pamphlets. 

Now it was Saturday morning and he and Tommy were going to Hogsmeade. Since the Fall of Voldemort, Hogwarts had slowly relaxed the restrictions on students so that now any student of year 6 or 7 could travel to Hogsmeade any weekend, so long as they had acceptable grades. The Headmistress had actually found that this greatly improved the number of students who successfully completed the N.E.W.T.-level classes.

Oliver was excited for the trip; he wanted to scout locations for a base nearby the school where he could keep the extra supplies he had brought with him. He was also looking forward to seeing his mother again. He had written to her, and she was going to meet them for lunch with Thea.

Tommy complained the entire walk to Hogsmeade, as he had wanted to take a carriage. Oliver was needling Tommy about his focus on getting to the Weasley’s joke store as fast as possible, and so didn’t immediately react when three masked men Apparated around them on the outskirts of town. 

They stunned Tommy, and Oliver drew his wand and tried to position himself so none of them was behind him. He was preparing to cast when one of the townswizards walked by. One of the masked wizards stunned Oliver, and as he fell to the ground he saw them cast the Killing Curse on the bystander. Then everything went dark for a while.

 

 

When Oliver came to again, he was secured to a chair and the men in masks were positioned around him. He thought he was in one of the empty buildings near where he had been grabbed.

“What did Robert Queen tell you about the Undertaking?” One of them demanded once they saw Oliver was awake.

“Why would I tell you?” Oliver scoffed, rolling his shoulder and checking his bindings for slack.

“Because of what will happen if you don’t. Crucio!”

Oliver gritted his teeth as the pain curse hit him, but didn’t say anything. It wasn’t the first time he had the target of the curse. He glanced around the room while they let him recover, and was glad to see Tommy. Oliver was even gladder to see Tommy was still out cold.

“Want to us to try that again?” the same masked wizard taunted. Oliver just sneered at him as he cast the curse again.

“Anything to say yet Queen?” another of the thugs sneered once the curse had ended.

“Yeah,” Oliver growled, “I’m going to make you eat that wand.”

“How? You’re tied to the chair,” the one who had been casting Crucio taunted.

Oliver just gave a feral grin and showed his hands. He tried not to savor the dawning realization in the eyes of the thugs. He lunged at the one standing near Tommy, and used him as a shield when another of the masked wizards sent a Killing Curse at him. He dropped the dead weight and lunged at the one who had just tried to kill him. Oliver grabbed his opponent’s wand hand while kicking the wizard who had Crucio’ed him in the gut. The torturer crumpled up, while the one he was grappling with dropped his wand. Oliver grimly smiled as he, in fact, made him eat it before yanking him up as a shield against a fire curse thrown by the last wizard. Oliver felt his human shield burst into flames, and threw him at the last wizard.

The last masked wizard panicked and dropped his wand when the flaming body flew at him. He gave Oliver a wide-eyed look of shock and ran out of the room. Oliver sighed and scooped the loose wand off the ground. He stopped to check that Tommy was still asleep before stalking off after the other wizard. He trailed the other wizard and slammed him into the wall before he could open a door to the street. Oliver shoved him back into corner and stood between him and escape, wand in hand.

“You don’t have to do this,” the masked wizard pleaded, backing up until he ran into a wall.

Oliver thought about the wizard they had killed in Hogsmeade, about what he had done, and what this torturer had seen him do. He thought about what his father had told him about the Undertaking, about what they would do to the world if he couldn’t stop them. He closed his eyes and took a deep breath. 

His face was clear of emotion as he looked at the man and said, “Yes. I do. Avada Kedavra.”

**Author's Note:**

> I tried to keep it Oliver, but also Oliver who's 18. I may have failed there...
> 
> If anyone has feedback/comments/questions or wants to help me beta-read, please let me know.


End file.
